The present invention is to provide a manufacturing method for manufacturing round keys through mass production.
FIG. 1 illustrates a round key for moving the bolt of a lock, which is generally comprised of a key rod 11 extending from a bow 1. The key rod 11 is milled or drilled to form two opposite inner walls 13, 13' defining therebetween a bitting 12 for driving the bolt of a lock. According to a conventional manufacturing process, a key rod is first drilled according to a pre-determined pattern to form a bitting therein along an axial direction. After the formation of the bitting 12, the key rod 11 is further trimmed to form two opposite, vertical inner walls 13, 13' at both sides of the bitting 12. By means of the bitting 12 matching with the two opposite inner walls 13, 13', the bolt of a corresponding lock is smoothly moved to lock or unlock a door or similar appliance. The disadvantage of this conventional round key manufacturing process is its low production efficiency which cannot achieve mass production. According to the aforesaid manufacturing process, only a few pieces of round keys can be produced at a time. More particularly, the surface trimming process must be made manually piece by piece. There is a kind of computer-controlled round key manufacturing machine for manufacturing round keys more efficiently. However, the cost of this kind of computer controlled round key manufacturing machine is very expensive and the round keys produced by such a machine must be surface trimmed by manual labor. Therefore, this computer controlled round key manufacturing machine still can not satisfy the requirement for integral mass production.